#include <stdio.h>  
int main()   
{  
   int n, count( );  
   scanf("%d", &n);  
   printf("%d\n", count (n, n-1));    
   return 0;  
}  
  

int count( int n, int m )   
{   
   if(n<1||m<1)return 0;
   else if(n==1||n==1)return 1;
   else if(n==m)return count(n,m-1)+1;
   else return count(n-m,m)+count(n,m-1);
}
